October 25 – Silver Lining

Scientists do their best work when faced with contradictory results. If you always get just one result, then what you are investigating isn’t very interesting. But if sometimes you see one thing and sometimes you see another, then that’s Nature’s way of telling you that you are on the verge of learning something truly neat.  And that’s what happens to Mary, Peter, and Daniel today as they look for the silver lining.

The atmosphere in Peter’s living room was just perfect for the Secret Science Society’s annual “Mad Science Movie Marathon”. While Mary, Peter, and Daniel indulged in huge bowls of popcorn, plates of caramel apples, and glasses of swamp juice (lemon soda with food coloring and raisins), classic monster movies from the 1950s ran on the DVD player and a fierce storm raged outside. They had laughed at The Mummy’s bad hieroglyphics, howled along with The Wolfman, and shivered as Frankenstein brought his creation to life with the lightning on the screen being echoed by real thunder from the storm outside. Naturally, just as the villagers gathered up their pitchforks to explain the homeowner association rules to poor, mad Victor, a bright flash of light and an ear-shattering crack told of a near-miss and the television and lights and all other power went off in the house.

“Don’t worry,” Peter said. “I know where the emergency flashlights are.”

“Rats!” said Daniel. “It was just getting good!”

“I wonder how long it will take to get the power back,” Mary mused. “And what will we do while we wait?”

“I’ve got a better question,” Daniel said. “Why is it dark?”

“Huh?” said Peter as he came back into the room with three flashlights.

“Think about it,” Daniel said. “When you look at a cloud on a sunny day, the cloud is white. Sometimes it even seems brighter than the sky around it. So why is it dark under a rain cloud? Aren’t they all the same thing?”

“I hadn’t thought about it,” Mary replied. “But you are right. Rain clouds are dark but regular clouds aren’t. I wonder why?”

“Well, it is too wet outside to go ask Mr. Medes,” Peter said. “Do you think my mom might know?”

“Might know what?” Peter’s mother asked as she came into the room with more flashlights. “I thought you might need these but I see you’ve got things well in hand!”

“Daniel asked something that we don’t know the answer to,” Mary said. “Why is it dark when it rains if clouds are white?”

“Well, there’s no shame in not knowing something. The only shame is if you don’t try to find out what the answer is,” Peter’s mother replied. “And it turns out that the answer to your question happens to apply to my work. So, yes, I know the answer.”

“What is it?” Daniel asked.

“Well, would you rather I told you or would you prefer to do an experiment?”

“Experiment! Experiment!” the three young scientists chorused.

“OK. Peter, go get that bag of marbles from your room,” his mother directed. “And I’ll go get some clear plastic bags from the kitchen. We’ve already got flashlights, so we’re all set.”

Peter quickly went to his bedroom and grabbed the bag of marbles. As he came back into the den, his mother returned with four plastic bags. Taking the marbles from Peter, she filled each bag with marbles before sealing it and handing it to one of the scientists.

“OK,” she said as she filled her bag with marbles. “This would work better if the marbles were clear instead of having that swirl of color in the middle, but it is close enough for our purposes. What I want you to do is shine your flashlight through the bag of marbles cross-wise so that the light goes through the ‘thin way’. What happens?’

“I can see the light but it is a bit fuzzy,” said Daniel.

“And the edge of some of the marbles gets bright,” added Mary.

“Good,” said Peter’s mother. “Now, what I want you to do is shine the light through the bag of marbles the long way. But, before you do, tell me – what will you see?”

“Probably the same thing we just saw,” said Peter. “The light will be fuzzy and there will be some bright edges.”

“I don’t know,” said Daniel. “Maybe having more marbles means that the light won’t make it through somehow.”

“Or maybe we’ll just see bright edges,” added Mary.

“Well, there’s only one way to find out!” Peter’s mother said.

What do you think will happen? Try the experiment yourself!

The three turned their baggies longwise and looked at the flashlight shining through. But instead of a bright light, they only saw a dull, fuzzy beam. The marbles had dimmed the flashlight beam just as clouds dulled sunbeams.

“Wow!” exclaimed Peter. “The light got a lot darker.”

“And most of the bright edges are gone!” said Mary.

“But why?” asked Daniel.

“The reason for this is the same reason that the bottom of the ocean is dark and that radio waves don’t travel very far in a nebula,” Peter’s mother said. “It is a type of physics known as optics. When the light from the sun or from a flashlight beam hits an object, three things happen: reflection, refraction, and absorption.”

“Reflection like a mirror?” Mary asked.

“Exactly! You may have noticed that you can see your face in a very still pond; that’s because some of the light that hit the top of the water was reflected back at you,” Peter’s mother explained. “The same thing happens with our marbles and with the raindrops that make up a cloud. Some of the light gets reflected back off of every raindrop. As you get deeper into the cloud or the cloud gets thicker, less and less light makes it through.”

“Oh, so that’s why rainclouds clouds are dark! They are thicker than other clouds!” Peter said.

“No, that’s only part of the explanation,” his mother replied. “There’s also refraction; that’s what happens when the light gets bent by the raindrop. Instead of traveling through and continuing in a straight line like a toothpick in an olive, the raindrop makes the path of the light shift a little so it looks more like a broken toothpick in an olive. And because the angle of the break is different for each color of light, when the angle is just right, you can get -“

“A rainbow!” Daniel said. “Is the bent light what made the edges of the marbles seem bright?”

“That’s exactly right,” Peter’s mother said. “Taken together, we sometimes refer to reflection and refraction as scattering. But reflection and refraction are only part of the reason that rain clouds are dark. The third reason is – “

“Absorption!” Mary said. “Is that like when a sponge absorbs water?”

“Not quite,” Peter’s mother said. “With a sponge, you can always get the water back out by squeezing it. But when light gets absorbed by a raindrop, it gets changed into heat. That added energy might make the raindrop warm up a very little bit or it might be re-radiated as infrared light. And since we can’t see in infrared, that makes it dark in the center of a rain cloud and under one, too.”

“But what does that have to do with the ocean bottom?” Peter asked.

“You can think of the ocean as a whole bunch of raindrops jammed together,” his mother replied. “As the light goes through the ocean, some of it gets absorbed. Interestingly, the depth that the light makes it down to depends on the wavelength of the light. Colors like red have very long wavelengths and make it deeper into the ocean than colors like blue. In addition, water like to scatter the shorter wavelength colors like blue; that’s why the ocean looks blue – more of that color gets reflected to your eyes. Taken all together, the amount of light that you can see in the ocean drops by 90% for every 75 meters. So if the ocean was as deep as a skyscraper is high, the bottom floor would get only 10% as much light as the top one would.”

“Cool!” Daniel said. “But what does that have to do with your work?”

“I’m a planetologist,” she replied. “That means that sometimes I look at planets before they are born, when they are just big clouds of gas and dust called nebulae. The gas and dust in a nebula will scatter and absorb light just like the water in the ocean or the raindrops in a cloud. And by measuring how the light from stars behind the nebula is scattered and absorbed, we can estimate the thickness of the cloud and even learn what it is made of. We’ve found water, ammonia, formaldehyde, and even amino acids in nebulae across the galaxy. There are even some scientists who think that life on Earth started thanks to those amino acids.”

“Neat!”

Just then, the power came back on.

“Well, it looks as if your creation has come back to life,” Peter’s mother said. “So I’ll just leave you three to your movies.”

“Thanks mom!” Peter said, his fingers already on the remote, ready to start the movie again as the three sat back down absorbed once more in the morality tale on the silver screen.

October 24 – Fine As Silk

Today’s factismal: The first nylon stockings went on sale in 1939.

Back in 1939, women had a big problem: they wanted to wear silk stockings but they couldn’t afford them. The price of a typical pair of silk stockings had risen by more than 50% in the past year alone, thanks to rising demand and embargoes on foreign goods. And even if she could afford the $0.69 ($11.26 in today’s money) that a pair of stockings cost, a woman was likely to see her investment ruined the first time that she wore them. Fortunately, chemistry was about to come to the rescue.

Artificial silk had been known since 1855 when nitrocellulose (aka guncotton or “oops! I blew your legs off”) was turned into fine, extremely flammable threads that became known as “mother-in-law’s silk”. The process was further refined into the creation of rayon from sawdust in the early 1920s, but the threads were coarse and irregular. So scientists searched for an alternative and finally found it in 1935. The nylon silk that they produced was first used to make bristles for toothbrushes; once the process had been refined enough to create long fibers, they started to manufacture stockings, parachute cloth, and other fabric goods.

A war poster encouraging recycling silk and other scarce goods (Image courtesy Truman Library)

A war poster encouraging recycling silk and other scarce goods
(Image courtesy Truman Library)

Their discovery came just in time as many of the traditional sources for rope (hemp from Indonesia), tires (rubber from Indonesia and Thailand), silk fabric (silk from China) and other materials had been embargoed due to concerns about the war that had begun. Thanks to their work, the US was able to substitute synthetic materials for the natural goods; today, many of those synthetic materials are not only still used but often preferred due to their superior quality and strength. If you’d like to learn more about the chemistry behind nylon and other synthetic fabrics, then head on over to Chemspider:
http://www.chemspider.com/

October 23 – It Is Full Of Stars

Today’s factismal: There are about as many atoms in 16 grams of oxygen as there are stars in the universe.

If you had been a chemist in the 1800s, you would have had a real problem. You knew for a fact that oxygen plus carbon would make water(H2O), but you would be able to say how much oxygen or how much hydrogen was needed to leave nothing but water in the reaction chamber. Sometimes you’d have oxygen left over and sometimes you’d have carbon left over and you’d always have a big mess. It was uncertainties like this that kept chemistry from being an exact science.

The reason that chemistry was an uncertain science was because the number of oxygen atoms in a pound of oxygen is different than the number of hydrogen atoms in a pound of hydrogen. Because chemistry takes place on the atomic scale, you couldn’t just add two pounds of hydrogen to one pound of oxygen and get nothing but water; you had to find some way of scaling the weight (or, more appropriately, the masses) of each chemical so that you’d be adding the right number of atoms. Fortunately, a scientist by the name of Avogardo pointed the way.

Avogardo (or “Avocado” as he is known to all freshman chemistry students) had the bright idea in 1811 that the volume of space taken up by a gas at a given pressure and temperature might be related to the number of atoms in that gas; based on that, he and other scientists were able to derive the relative atomic weights of the elements. It took the chemists nearly a century, but by 1909, we had a periodic table that listed the atomic weight of each element. That allowed us to know exactly how much of each to add in order to get reactions that worked perfectly every time.

There are a mole of stars in the universe (Image courtesy NASA)

There are a mole of stars in the universe
(Image courtesy NASA)

Avogardo and the chemists who came after him called the standard amount of stuff a mole (short for “molecular volume”). And, because it was Avogardo’s bright idea that made it all possible, the number of atoms (or molecules) in a mole is known as Avogardo’s number. And it is a mighty large number – there are 6.02 x 10^23 atoms of oxygen in 16 grams (one mole) of oxygen. To give you an idea of how many atoms that is, just go outside tonight and take a look at the night sky. If you were to count every star in every galaxy in the universe, there would be about 10^23 stars. So there are as many atoms of oxygen in a mole of oxygen as there are stars in the mole of the universe!

Chemists celebrating Mole Day (Image courtesy ACS)

Chemists celebrating Mole Day
(Image courtesy ACS)

In honor of Avogardo’s discovery, today is Mole Day (because it is 10/23 – get it?). So take part in a mole day celebration somewhere. Go eat a mole cake and drink some mole juice. And then make a un-moley mess, just so you can appreciate why chemists were so happy to become an exact science!
http://www.acs.org/content/acs/en/education/students/highschool/chemistryclubs/activities/mole-day.html

October 22 – Against The Fading Of The Light

Today’s factismal: The last solar eclipse of 2014 takes place tomorrow evening at 3:30 PM EDT (assuming that you live in Alaska).

If you live anywhere in North America, get ready! You won’t want to miss the last eclipse of 2014. It happens tomorrow afternoon at 3:30 PM and will be visible across the entire continent. Though this will only be a partial eclipse, thanks to the Moon’s angle with the Sun, it nevertheless promises to be a spectacular show.

Tomorrow's eclipse (Image courtesy NASA)

Tomorrow’s eclipse
(Image courtesy NASA)

 

Local Eclipse Times
City Eclipse Starts Eclipse Ends
 Anchorage, AK  11:55 AM 2:28 PM
 Baltimore, MD  5:51 PM  6:15 PM
 Baton Rouge, LA  5:02 PM  5:59 PM
 Dallas, TX  4:48 PM  5:43 PM
 Oklahoma City, OK  4:40 PM  5:48 PM
 Portland, OR  1:37 PM  4:22 PM
 Richmond, VA  5:55 PM  6:21 PM
 Tallahassee, FL  6:09 PM  6:56 PM
 Denver, CO  3:18 PM  5:44 PM

Of course, eclipses don’t just happen in one year; we have some every year. There will be four eclipses in 2015. On April 4, before you pay your taxes, you can see a total lunar eclipse from the central US through all of Europe and Africa. On March 20, you can watch the total solar eclipse if you live in the middle of the north Atlantic Ocean (great if you are a fish). On September 15, there will be a partial solar eclipse that will be most visible if you happen to be a penguin; outside of Antarctica and parts of Australia, it won’t be visible at all. Then on September 28, there will be another total lunar eclipse; this time it is visible mostly over Asia. If you’d like to learn more about eclipses, including if you’ll be able to see any of the four eclipses visible next year, then head on over to the NASA Eclipse Web Site:
http://eclipse.gsfc.nasa.gov/eclipse.html

October 21 – Ka-Boom!

Today’s factismal: The world’s most famous chemist is known mostly for his charitable work.

Mining in the 1800s was a nerve-wracking job. Not only did you have to worry about bad air, cave-ins, and flooding, but the explosive of choice was almost as unstable as your boss. Known as nitroglycerin, it was easy and cheap to make but tricky and difficult to transport and use. It would go off if it got too hot or too cold, if it was jostled too much or not enough, or if it just didn’t like the way you looked at it. It frequently destroyed the factories where it was being made, and its habit of exploding while being moved led to laws against it being transported across state lines.

But in 1867, Alfred Nobel found a way to tame the beastly blast. By mixing the nitroglycerin with diatomaceous earth or sawdust, he was able to make it more stable and less dangerous. It could be easily stored and transported and could even be measured on the spot with very little chance of losing an arm. Needless to say, dynamite was an immediate hit and made Alfred Nobel very, very rich indeed. But every silver lining has a cloud, and dynamite had a big one.

Because nitroglycerine was so unstable, no sane Army would use it. But because dynamite was so stable, it immediately became the basis for new and more powerful weapons. Nobel knew this and it didn’t particularly bother him (his family fortune was founded in arms manufacturing), but it did upset a lot of other people. And when Alfred’s brother Ludvig died, he got an idea of just how much it bothered other folks. A French newspaper thought that it was Alfred that died, and took the opportunity to write one of the most scathing obituaries ever seen. The nicest thing that they called him was a “merchant of death”. Alfred was mortified.

He decided to redeem his family name. And, since science had gotten him into this predicament, he decided that science would get him out of it. He established the Nobel Prize, which was given out every year for the most important work in physics, chemistry, literature, and (in a deliberately ironic twist) peace. (Later groups would add an economics prize.) The Nobel Prize has become the gold standard of work and worth in the sciences and continues to this very day. Evey year on his birthday, the prizes are awarded in the name and memory of the most famous chemist ever to live.

If you’d like to learn more about this year’s winners in chemistry, then head over to:
http://www.scientificamerican.com/podcast/episode.cfm?id=the-2013-nobel-prize-in-chemistry-k-13-10-09

October 20 – Bigger Than Big

Today’s factismal: The giant squid Architeuthis (“chief squid”) isn’t the biggest squid in the ocean but it is the longest.

There is no creature more fabled and fabulous than the giant squid. Mentioned in literature from the time of the Bible and featured in books as diverse as 20,000 Leagues Under The Sea and Moby Dick, it is known more by rumor than by fact. That’s because old Architeuthis (Archie to his friends) is a shy critter who prefers hiding in the deep water (the better to nab his favorite snack of other squids) to gamboling about where people can see him. Until very recently, Archie was known more by implication than by actual fact.

Architeuthis sucker scars on sperm whale skin (Image courtesy Magell Inc)

Architeuthis sucker scars on sperm whale skin
(Image courtesy McMillan Company)

What sort of implication? Consider the sperm whale. These behemoths love to munch on fish and squid, and (given their size-driven appetite) the bigger, the better. So it is only natural that sperm whales would chase down big squid like Archie and ask them to dinner. And it is only natural that Archie would vigorously decline the invitation, leaving giant sucker marks on the whale. Of course, when the whale would win the argument, there’d be the beak (the part that proves a squid to be a mollusc) left as an undigestible lump in its stomach which would be found when whalers insisted on the sperm whale joining them for a bite.

Until 2004, this was the only way we found giant squid  (Image courtesy Enrique Talledo)

Until 2004, this was the only way we found giant squid
(Image courtesy Enrique Talledo)

And then there were the rare sightings. Originally taken for nothing more than sailor stories, they acquired a great deal more importance once the sailors started backing up their tales with something more than scrimshaw. By the mid 1800s, we knew that there was a giant squid living in the ocean. But that was about all that we knew. It wasn’t until 2004 that images of a giant squid swimming around and chasing other squid surfaced. Since then, there have been many more sightings, but we continue to learn more about Archie.

Why they named it "Middle clawed" (Image courtesy Theudericus)

Why they named it “Middle clawed”
(Image courtesy Theudericus)

Including the fact that though Archie is the longest squid out there (a whopping 43 ft long from tip to tail for the women and 33 ft for the men), it is not the most massive squid in the oceans (“just” 606 lbs for the lady squids and a mere 303 lbs for the gents). Instead, the colossal squid known as Mesonychoteuthis hamiltoni (“Hamilton’s middle clawed squid”) that lives in the waters near Antarctica outweighs it by a large margin; the largest recorded specimen of Hamie weighed 1,091 lbs! (Imagine half a ton of angry squid headed toward you…) However, though old Hamie is fat, he isn’t very long; they are only about 33 ft from tip to tail when grown.

So what can we learn from these not-so-gentle giants? First and foremost, there are plenty of exciting things still left to discover. From bigger-than-giant squids to smaller than a pin microbes, life is amazingly diverse and new discoveries lurk around every corner. Second, most of the sightings of Archie and Hamie happened when ordinary folks (that’s you and me) happened to see something and reported it to researchers. If you’d like to help, then why not join the Washington NatureMappers or start a project like that in your area?
http://naturemappingfoundation.org/natmap/

October 19 – A New Low

Today’s factismal: The most intense Atlantic hurricane ever recorded was Wilma, with a low pressure in the eye of just 882 mbar.

If you are a meteorologist, then 2005 is probably your favorite year. Over the course of the year, there were so many tropical storms that they ran out of names and had to resort to using Greek letters. Of the 28 storms that developed, a record high of 15 would go on to become hurricanes and seven of those would become major hurricanes. And none of those was more major than Wilma.

Wilma at peak strength (Image courtesy NASA)

Wilma at peak strength
(Image courtesy NASA)

Wilma started as a tropical depression off of Jamaica on October 15. Two days later, she had become a tropical storm. By the 18th, she was a full-fledged hurricane and showing no signs of getting any weaker. Indeed, where most hurricanes are big, ungainly monsters with large eyewalls (which often indicates a weaker storm), Wilma had a fairly compact eyewall just two miles across (the smallest known) and peak winds of 185 mph! Those factors combined to give Wilma the lowest known pressure of any hurricane at just 882 mbar; to put that in perspective, remember that normal air pressure at sea level is 1013 mbar. In effect, the center of Wilma was at the same air pressure as Denver!

Naturally, a storm this intense caused lots of damage. Wilma killed at least 62 people (mostly through flooding and landslides) and caused $29 billion dollars in damage. Many of the deaths happened because Wilma’s path was unusually unpredictable; she changed directions several times, making it harder to know where she would hit. What the meteorologists needed was more observations in order to give better predictions. What they needed was people like the members of the Citizen Weather Observer Program who send in reports about severe weather (and the other kind, too) that is then used to make better predictions. If you think that you’ve got what it takes to be a CWOP member, head over to:
http://wxqa.com/